Field of the Invention
The present invention relates to a circuit arrangement for setting a type carrier which carriers character types in the region of its periphery, from a present setting position on the shortest path of rotation to a new setting position via a stepping motor by means of pulse train elements which are derived from information characters input in binary form, where the relevant position of the type carrier can be read as a binary coded position character, in business machines, data machines, teleprinters or the like.
Description of the Prior Art
In contrast to arrangements in which type carriers equipped with a plurality of types can be set by an aggregate motion transmission only within a setting angle of 360.degree., the setting possibilities in arrangements provided with servomotor or stepping motor drive systems for type carriers of this type are not subject to functional limits, i.e. mechanically the type carrier can be set from a set position into another desired position both in the one direction and in the opposite direction of rotation. In order to achieve the desired position for the type carrier as rapidly as possible, it is advantageous to select the shortest setting path. Mechanical transmissions are known which, operating under complicated laws of motion, set a type carrier in the direction of rotation into the next desired position by the shortest path of rotation. When stepping motors are used to set type carriers, a simple method of calculating the setting rotation direction is achieved, which can be executed with electronic switching units, when the type carrier possesses a total of 2.sup.n setting positions, because, in fact, the electronic elements are normally organized in binary form.
A teleprinter for n-element codes is known in the art, which teleprinter has a type cylinder which can be adjusted, by rotation, in both directions by means of a stepping motor, as set forth in the German published application 2,154,899, wherein, in order to attain the next peripheral position of the type carrier to be set, from the last setting which was occupied, over the shortest possible path, a test binary counter is provided which can be set in the forward direction with a multiply higher pulse train, e.g. with a 200 kHz pulse train, and in which the requisite setting of the binary counter can be simulated, and that a pulse train counter is provided which can be controlled via this test binary counter, and which, whenever it is estimated that half the number of the print-out positions along the periphery, or less, is required to reach the end position, adjust the stepping motor in the forward direction, and when this number is overshot adjusts the stepping motor in the reverse direction.
With the aid of this known circuit arrangement, independently of the total number of type characters arranged on the periphery of a type character, it is possible to predetermine the direction of adjustment in which the type carrier is to be moved from a starting position into the next print-out position by the shortest path. On the other hand, the adjustment quantity is not determined, but the adjusting motion is terminated when, in a comparison of the drive value with the relevant position value of the type carrier, these two values are identical. However it is important to determine the adjustment quantity when the type carriers can be adjusted by controlled servo-motors, or in particular by stepping motors, and drive programs having acceleration and deceleration phases are to be used for longer adjustment paths.